Chemical deepwater stimulation systems and methods.

ABSTRACT

Systems and methods for performing operations on a well include first and second flow control devices positioned between upper and lower sections of a conduit. An upper connector assembly engaged with the upper section includes connectors adapted for connection to a chemical stimulation device, a blowout preventer, or other well intervention apparatuses. A lower connector assembly engaged with the lower section includes connectors adapted for connection to a chemical stimulation device, a running tool, wellbore conduits, or other well intervention apparatuses. The two connector assemblies, above and below the flow control devices, enable sequential or simultaneous operations to be performed, and can enable operations to be performed independent of the state of the flow control devices.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority to and thebenefit of, U.S. patent application Ser. No. 14/999,000, having thetitle of “Chemical Deepwater Stimulation Systems And Methods,” filed onMar. 14, 2016, which is a continuation-in-part of, and claims priorityto and the benefit of, U.S. Pat. No. 9,284,808, having the title of“Chemical Deepwater Stimulation Systems And Methods,” filed on Dec. 5,2012.

FIELD

Embodiments usable within the scope of the present disclosure relate,generally, to systems and methods usable to perform chemical (e.g.,acid) stimulation operations on a wellbore, in combination with otherwell intervention operations, while minimizing or eliminating thedowntime normally required to remove, reposition, and/or replaceequipment.

BACKGROUND

Acid stimulation is frequently used as a form of well intervention torestore production of a well to peak levels. Conventional methods foracid stimulation require use of large rigs and risers, while alternativesystems can use remotely operable vehicles (ROVs), multi-service vessels(MSVs), or similar devices to access a wellhead in deep water, e.g.,using coiled tubing ballasted with weight to ensure proper descent andstabilization over a working area. A significant length of conduit(e.g., 150 feet) is often necessary to ensure that the flying leads andconnectors of the tubing can accommodate vessel heave and positiondeviation while allowing ample room for the front panel on the injectiontool at the wellhead to be accessed.

When a well stimulation and/or an injection tool is engaged with asubsea well tree, other intervention operations are inhibited and/orrendered impossible, resulting in a significant downtime between wellsimulation and other intervention operations and necessitating thereplacement and use of various equipment.

Conventional methods allow for acid injection via subseaumbilical/flying leads, e.g., through the installation of an acid toolthat latches onto a tree via a tree running tool. Such methods allow forinjection, but do not allow the wellbore to be accessed and/or onlyenable access via steel tubing and/or hosing. Thus, items having largeouter diameters, such as an internal tree plug or wireline tools, cannotenter the wellbore. Essentially, wireline equipment cannot be operatedwithin an umbilical or similar conduit due to the inherent physicalconstraints of the umbilical.

The limitation of equipment and methods that only permit injection ofacid without having the ability to enter the well using wirelineequipment contributes to operational downtime, as a separate pressurecontrol assembly (e.g., a blowout preventer) is then needed to accessthe well with wireline equipment.

A need exists for systems and methods that enable both well stimulationoperations and other intervention operations to be conducted, whileminimizing the replacement of equipment and downtime therebetween, whilemaintaining at least two barrier valves to isolate the wellbore.

A further need exists for systems and methods that enable running ofwireline equipment while providing at least two isolation barriers, thetwo or more barriers being closable to allow chemical injection to takeplace via placement of isolation barriers in an exterior portion (e.g.,“wings”) of the system.

A need also exists for systems and methods that can be operatedriglessly, or alternatively using only a small hoist and/or amulti-service vessel, eliminating the need for conventional rig andriser-based installation procedures. A lubricator and/or a “greasehead”can be used to create a seal during such rigless wireline operations.

SUMMARY

Embodiments usable within the scope of the present disclosure relate tosystems usable for performing operations on a well that include aconduit (e.g., a central conduit in communication with a wellbore)having an upper section and a lower section. A first flow controldevice, such as a barrier valve or other similar types of valves (e.g.,ball valves or hydraulic valves), regulators, and/or devices usable tolimit, divert, or prevent the flow of fluid, can be positioned betweenthe upper and lower sections of the conduit. Similarly, a second flowcontrol device can be positioned beneath (e.g., in a downhole direction)the first flow control device, between the upper and lower sections ofthe conduit, thereby forming a double-barrier usable to isolate thewellbore.

An upper connector assembly can be engaged with the upper section of theconduit for enabling communication therewith. The upper connectorassembly can include a first flow cross member in fluid communicationwith the first flow control device, the first flow cross member enablingfluid flow in at least two directions. The upper connector assembly canfurther include a connector adapted for connection to a chemicalstimulation device (e.g., an acid stimulation unit) or a similar wellintervention apparatus, and a top connector, usable for engagement witha blowout preventer, and/or for performing chemical stimulation, and/orfor plug and abandonment, and/or for subsea remediation, and/or otherwell intervention operations therethrough.

Similarly, a lower connector assembly can be engaged with the lowersection of the conduit and includes a second flow cross member in fluidcommunication with the second flow control device, the second flow crossmember enabling fluid flow in at least two directions. The lowerconnector assembly can include a connector adapted for connection to achemical stimulation device or a similar well intervention apparatus,and a bottom connector adapted for engaging a running tool, a wellboreconduit, a blowout preventer, or combinations thereof.

Pump in lines can be engaged with the connectors of either or both ofthe upper and lower connector assemblies, to be used for chemicalstimulation, connection to a tree running tool, or other interventionoperations, without requiring installation of additional equipment.Thus, the upper connector assembly can be used to perform stimulationand/or other intervention operations through a pump in line and/or thetop connector, through the first and second flow control devices (e.g.,when the flow control devices are open to permit fluid flow and/orpassage of other materials), and/or to accommodate a blowout preventer,while the lower connector assembly can be used to perform stimulationand/or other well operations independent of the first and second flowcontrol devices (e.g., even when the barrier valves or similar flowcontrol devices are closed). Thus, for example, the bottom section ofthe system could be used for well stimulation while the top section isused for other well operations, simultaneously or in combinationtherewith. The connectors of either or both of the upper and lowerconnector assemblies can include emergency quick disconnect (EQD)members to enable rapid disconnection when necessary to close the systemand ensure safe operation and/or departure of any vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

In the detailed description of various embodiments usable within thescope of the present disclosure, presented below, reference is made tothe accompanying drawings, in which:

FIG. 1 depicts a diagrammatic side view of an embodiment of a systemusable within the scope of the present disclosure.

FIG. 2 depicts a diagrammatic side view of an alternate embodiment of asystem usable within the scope of the present disclosure.

FIG. 3 depicts a diagrammatic side view of another embodiment of asystem usable within the scope of the present disclosure.

FIG. 4 depicts a diagrammatic side view of an additional embodiment of asystem usable within the scope of the present disclosure.

FIG. 5 depicts a diagrammatic side view of another embodiment of asystem usable within the scope of the present disclosure.

One or more embodiments are described below with reference to the listedFigures.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Before describing selected embodiments of the present disclosure indetail, it is to be understood that the present invention is not limitedto the particular embodiments described herein. The disclosure anddescription herein is illustrative and explanatory of one or morepresently preferred embodiments and variations thereof, and it will beappreciated by those skilled in the art that various changes in thedesign, organization, order of operation, means of operation, equipmentstructures and location, methodology, and use of mechanical equivalentsmay be made without departing from the spirit of the invention.

As well, it should be understood that the drawings are intended toillustrate and plainly disclose presently preferred embodiments to oneof skill in the art, but are not intended to be manufacturing leveldrawings or renditions of final products and may include simplifiedconceptual views as desired for easier and quicker understanding orexplanation. As well, the relative size and arrangement of thecomponents may differ from that shown and still operate within thespirit of the invention.

Moreover, it will be understood that various directions such as “upper,”“lower,” “bottom,” “top,” “left,” “right,” and so forth are made onlywith respect to explanation in conjunction with the drawings, and thatthe components may be oriented differently, for instance, duringtransportation and manufacturing as well as operation. Because manyvarying and different embodiments may be made within the scope of theconcepts herein taught, and because many modifications may be made inthe embodiments described herein, it is to be understood that thedetails herein are to be interpreted as illustrative and non-limiting.

Embodiments usable within the scope of the present disclosure relate tosystems and methods usable to perform wellbore intervention operations(e.g., chemical stimulation, tubular running, and/or other similaroperations) without requiring removal, repositioning, and/or replacementof existing equipment to perform different operations, and in anembodiment, without requiring use of a rig or similar maneuveringequipment.

Conventional methods for performing chemical stimulation operationsrequire use of a large rig to hoist risers into place and run theserisers from a large vessel to the wellbore. After a chemical stimulationoperation is performed, the required equipment must be removed andreplaced with other equipment for performing additional interventionoperations. Embodiments usable within the scope of the presentdisclosure overcome these and other limitations of existing systems andmethods.

Referring now to FIG. 1, a diagrammatic side view of an embodiment of asystem (10) usable within the scope of the present disclosure is shown.The system (10) includes a central conduit (12) positioned above awellbore (e.g., in an uphole direction relative to the wellbore), anadditional conduit communicating with a wellbore, and/or a running tool(not shown). The central conduit (12) includes an upper section (14) anda lower section (16). It should be noted that the division of theconduit (12) into upper and lower sections (14, 16) is a conceptualdivision to facilitate clarity, and does not necessarily require thatthe conduit (12) include multiple separable members, as depicted.Embodiments usable within the scope of the present disclosure caninclude integral and/or unitary conduits, or conduits having any numberof physical components.

As shown, a first flow control device (18) and a second flow controldevice (20), which can include ball valves, hydraulic valves, and/orother similar devices usable to restrict, regulate, prevent, and/ordivert fluid flow, are positioned between the upper and lower sections(14, 16) of the conduit (12), enabling isolation of the upper section(14) from the lower section (16), and enabling isolation of the wellborefrom the upper section (14) and/or the environment external to theconduit (12).

The upper section (14) is shown having an upper connector assembly thatincludes a first flow cross member (22) (e.g., a 4 1/16″ 10M flowcross), a first connector (24) that is shown engaged with a first pumpin line (26) (e.g., a 2″ 15M pump in line), and a top connector (28),that is usable for engagement with a blowout preventer, a chemicalstimulation apparatus, and/or other apparatuses for performing wellintervention operations (an exemplar of which is depicted in FIG. 5).The first pump in line (26) is shown including two barrier valves (30A,30B), and an emergency quick disconnect connector (32) (e.g., a 2″ EQDconnector) usable for engagement with a chemical stimulation unit, atree running tool, and/or with other devices for performing interventionoperations (not shown). The emergency quick disconnect connector (32)can be used for rapid disengagement from the system (10) when it isdesirable to quickly isolate the system (10) and/or to move an apparatusor vehicle away from the system (10).

The lower section (16) is shown having a lower connector assembly thatincludes a second flow cross member (34), having a second connector (36)that is shown engaged with a second pump in line (38), and a bottomconnector (40), usable for engagement with a running tool, a wellboreconduit, or similar conduits and/or apparatuses (not shown). The secondpump in line (38) is shown having two barrier valves (42A, 42B), and anemergency quick disconnect connector (44), usable for engagement with achemical stimulation unit and/or to perform other interventionoperations (not shown). The emergency quick disconnect connector (44)can also be used for rapid disengagement from the system (10) when it isdesirable to quickly isolate the system (10) and/or move an apparatus orvehicle away from the system (10).

In use, a first operating and/or intervention apparatus and/or achemical stimulation device can be engaged with the upper section (14)of the central conduit (12), above the flow control devices (18, 20),e.g., via the first flow cross member (22) and/or the top connector(28), while a second operating and/or intervention apparatus can beengaged with the lower section (16), e.g., via the second flow crossmember (34). For example, a blowout preventer can be engaged to the topconnector (28) while a chemical stimulation unit is engaged to theemergency quick disconnect connector (32) of the first pump in line(26), while a running tool is engaged to the bottom connector (40) andan additional chemical stimulation unit or other intervention apparatusis engaged to the emergency quick disconnect connector (44) of thesecond pump in line (38).

Chemical stimulation, and/or other intervention operations, can beperformed through the flow control devices (18, 20) via the first flowcross member (22) (e.g., via the first pump in line (26) or firstconnector (24) and/or the top connector (28)).

Referring briefly to FIG. 5, one possible configuration usable forchemical stimulation is depicted including a Y-block (21) located abovethe top connector (28) via a modular receiver (19) attached to the topconnector (28) and a modular connector (in this embodiment, acting as across connection) (25) connecting the Y-block (21) and the modularreceiver (19) through a barrier valve (23) and elbow joint. The Y-block(21) is utilized for complex operations which require two fluid inputsto be pumped simultaneously and mixed in situ, as depicted by the dottedoutline of (21) showing inputs (27A, 27B) leading into a mixing chamber.

The two inputs (27A, 27B) of Y-block (21) are each controlled by anindependent emergency quick disconnect connector (29A, 29B) whichcontrols the respective input to Y-block. It can be appreciated that theelbow connection is only one possible configuration usable forstimulation and not intended to be limiting; other embodiments may havestraight connections or connections at shallower angles, or the inputs(27A, 27B) may be angled rather than the conduit between barrier valve(23) and modular receiver (19).

Additionally (e.g., simultaneously, sequentially, or alternatively),other intervention operations can be performed independent of the stateof the flow control devices (18, 20) via engagement to the lower section(16) via the second flow cross member (34) (e.g., through the bottomconnector (40) and/or the second connector (36) or second pump in line(38)). Further, the open bore extending throughout the depicted system(10) (e.g., from the top connector (28) through the flow control devices(18, 20) to the bottom connector (40)) enables wireline operations andsimilar interventions to be performed independent of other operationsperformed using the first and second connectors (24, 36) and/orassociated pump in lines. As such, the depicted system (10) could beused to enable rapid performance of wireline operations to remove and/oractuate one or more plugs (e.g, through the top connector (28) andcentral bore of the system (10)), immediately prior to performingchemical stimulation operations through the first and/or secondconnectors (24, 36, respectively), without requiring substantialreconfiguration, removal, and/or replacement of components.

During use, the upper section (14) can be isolated from the lowersection (16) and/or the wellbore below using the flow control devices(18, 20), and from the environment external to the system (10) via thebarrier valves (30A, 30B) or similar devices. The lower section (16) canbe isolated from the upper section (14) using the flow control devices(18, 20), and from the environment external to the system (10) using theflow control devices (18, 20) and/or the barrier valves (42A, 42B) orsimilar flow control devices.

Referring now to FIG. 2, a diagrammatic side view of an embodiment of asystem (46), usable within the scope of the present disclosure, isshown. The depicted system (46) includes an upper flow cross member (48)having a side connector (50) adapted for engagement with pump in linesand/or intervention apparatuses, a top connector (52) similarly adaptedfor engagement with lines and/or apparatuses, and a central bore (54)for accommodating fluid flow and/or passage of apparatuses and conduits(e.g., wireline). The system (46) is shown having a lower flow crossmember (56), having a side connector (58) adapted for engagement withpump in lines and/or intervention apparatuses, and a bottom connector(60) adapted for engagement with a wellbore conduit, a running tool, orother similar apparatuses. The lower flow cross member (56) includes acentral bore (62) in communication with the bottom connector (60) (e.g.,for communication with wellbore tubing and/or casing), and a secondarybore (64) in communication with the side connector (58) (e.g., forcommunication with a wellbore annulus).

A conduit (66) is positioned between the upper and lower flow connectors(48, 56), the conduit (66) having a bore (68) that aligns with the bores(54, 62) of the flow connectors (48, 56) to form a continuous boreextending through the system (46), that can be accessible through thetop connector (52), the bottom connector (60), and the side connector(50) of the upper flow cross member (48). Positioned within the conduitare four flow control devices (70A, 70B, 70C, 70D), which are depictedas hydraulic valves, each having a movable member with a throughbore(72A, 72B, 72C, 72D) extending therethrough. When in an open position,the throughbores (72A, 72B, 72C, 72D) are moved into alignment with thebore (68) of the conduit (66), while when in a closed position, thethroughbores (72A, 72B, 72C, 72D) are moved out of alignment with thebore (68), such that the body of the valves blocks the flow of fluidthrough the bore (68). Each of the depicted flow control devices (70A,70B, 70C, 70D) can be actuatable (e.g., in a linear direction) usingcorresponding actuators (74A, 74B, 74C, 74D), which can be powered by,e.g., a hydraulic supply (76) that communicates fluid through a controlumbilical (78) or similar hydraulic conduit via a lower junction plate(80). Fluid can similarly be communicated through other junction plates,e.g., a middle junction plate (82) and an upper junction plate (84), toactuate additional components (86A, 86B), such as a blowout preventerand/or hydraulic connectors for securing thereto. The depicted system(46) is shown including independent hydraulic access points (90A, 90B,90C) that can be independently accessed (e.g., by a remotely operablevehicle) to individually actuate and/or access the actuators (74A, 74B,74C, 74D) or other components (86A, 86B). To provide a contingency foran uncontrolled scenario, a shear pin (88) can be provided to enableimmediate disconnection of the hydraulic supply (76) from the system(46).

The depicted system (46) is thereby usable to perform chemicalstimulation and/or other intervention operations through the topconnector (52) or the side connector (50) of the upper flow cross member(48) to access the wellbore conduit, and through the side connector (58)of the lower flow cross member (56) to access the annulus. Due to thecontinuous inner bore extending through the system (46), wirelineoperations and/or the passage of tools and apparatuses therethrough arealso possible, simultaneously with or sequentially following otheroperations performed via the side connectors (50, 58). Hydraulic accesspoints (90A, 90B, 90C) can be usable to access the actuators (74A, 74B,74C, 74D) and components (86A, 86B), as described previously.

Referring now to FIG. 3, a diagrammatic side view of an embodiment of asystem (47), usable within the scope of the present disclosure, isshown. The depicted system (47) is substantially similar to that shownin FIG. 2, having flow cross members (48, 56) disposed on opposing endsof a conduit (66) having flow control devices (70A, 70B, 70C, 70D)therein, which can be actuated by actuators (74A, 74B, 74C, 74D). Theactuators (74A, 74B, 74C, 74D) and associated wellbore components (86A,86B) can be powered using hydraulic supply (76) via a control umbilical(78), which can flow hydraulic fluid via junction plates (80, 82, 84).The depicted system (47) is shown having a plurality of accumulators(92) in communication therewith, and further in communication with aseries of vents (96). The accumulators (92) can be recharged via ahydraulic access point (94), and can be used to actuate a flexiblejumper via an access point (98). In an emergent situation and/or invarious other contingencies, the accumulators (92) can be used toactuate the flow control devices (70A, 70B, 70C, 70D), and/or to actuateor disconnect other system components.

Referring now to FIG. 4, a diagrammatic side view of an embodiment of asystem (100) usable within the scope of the present disclosure is shown.The depicted system (100) is substantially similar to that shown in FIG.3, having flow cross members (48, 56) disposed on opposing ends of aconduit (66) having flow control devices (70A, 70B) therein, which canbe actuated by actuators (74A, 74B). The actuators (74A, 74B) andassociated wellbore components (86A, 86B) can be powered using ahydraulic supply via a control umbilical (78), which can flow hydraulicfluid via conduits that engage quick disconnect plates (102, 104), whichcan be separated (e.g., via a shear pin) during an uncontrolledscenario. The depicted system (100) is shown having a plurality ofaccumulators (92) in communication therewith, which can be used toactuate the actuators (74A, 74B) and/or other components. Anintervention tool (106) (e.g., a subsea tree or similar apparatus) isshown engaged with the lower flow cross member (56) for communicatingwith the secondary bore (64) therein. While the actuators (74A, 74B),wellbore components (86A, 86B), and/or the intervention tool (106) canbe actuated using the control umbilical (78), or, if necessary, theaccumulators (92). FIG. 4 also depicts a plurality of access points(108), through which one or more of the actuators (74A, 74B), wellborecomponents (86A, 86B), or the intervention tool (106) can be operated,and through which the accumulators (92) can be recharged, such asthrough use of a Remotely Operable Vehicle or similar means. The accesspoints (108) are shown associated with various combinations of switches,vents, and/or valves.

Embodiments usable within the scope of the present disclosure therebyprovide systems and methods that enable both well stimulation operationsand other intervention operations (plug & abandonment, subsearemediation) to be conducted, simultaneously or sequentially, withoutrequiring removal and/or replacement of equipment, while enablingportions of the system or the entire system to be isolated as needed.Additionally, embodiments usable within the scope of the presentdisclosure can be operated riglessly and/or using a minimum ofequipment, eliminating the need for time consuming use of rigs, risers,and other conventional equipment and conduits.

While various embodiments usable within the scope of the presentdisclosure have been described with emphasis, it should be understoodthat within the scope of the appended claims, the present invention canbe practiced other than as specifically described herein.

What is claimed is:
 1. A system for performing operations on a well, thesystem comprising: a conduit having an upper section and a lowersection; a first flow control device positioned between the uppersection and the lower section; a second flow control device positionedbeneath the first control device and between the upper section and thelower section; and an upper connector assembly engaged with the uppersection, wherein the upper connector assembly comprises: a first flowcross member in fluid communication with the first flow control device,wherein the first flow cross member enables fluid flow in at least twodirections; a first connector connected to a chemical stimulationdevice; and a top connector connected to a blowout preventer, a wellintervention apparatus, or combinations thereof, wherein the upperconnector assembly enables simultaneous or combined operations performedusing the chemical stimulation device, the blowout preventer, the wellintervention apparatus, or combinations thereof
 2. The system of claim1, further comprising: a lower connector assembly engaged with the lowersection, wherein the lower connector assembly comprises: a second flowcross member in fluid communication with the second flow control device,wherein the second flow cross member enables fluid flow in at least twodirections; a second connector adapted for connection to a chemicalstimulation device; and a bottom connector adapted for engaging arunning tool, a wellbore conduit, a blowout preventer, or combinationsthereof.
 3. The system of claim 1, wherein at least one of the firstflow control device or the second flow control device is actuatableusing corresponding actuators powered by hydraulic fluid through theconduit via at least one junction plate.
 4. The system of claim 2,wherein the first connector, the second connector, or combinationsthereof, comprise an emergency quick disconnect connector.
 5. The systemof claim 1, wherein the first flow control device, the second flowcontrol device, or combinations thereof, comprise a ball valve, ahydraulic valve, or combinations thereof.
 6. The system of claim 2,further comprising a first pump in line engaged with the first flowcross member, a second pump in line engaged with the second flow crossmember, or combinations thereof.
 7. The system of claim 1, wherein thefirst flow cross member comprises a first primary bore and a firstadditional bore fluidly connected with the first primary bore, whereinthe second flow cross member comprises a second primary bore and asecond additional bore, and wherein the second additional bore isfluidly isolated from the second primary bore.
 8. The system of claim 1,wherein the well intervention apparatus comprises a Y-block, wherein theY-block comprises at least two inputs and at least one output, andwherein the at least one output is connected to the upper connectorassembly.
 9. The system of claim 8, wherein the well interventionapparatus further comprises at least two emergency quick disconnectconnectors, operably connected to the at least two inputs.
 10. Thesystem of claim 8, wherein the at least one output of the Y-block isconnected to the upper connector assembly at an angle.
 11. The system ofclaim 8, wherein the Y-block further comprises a mixing chamber therein.12. The system of claim 1, where the simultaneous or combined operationsperformed comprise well stimulation, well intervention, plug andabandonment, subsea remediation, or combinations thereof.